Low-temperature titania coatings for aluminium corrosion protection

Abstract

TiO 2 coatings on AA6082 aluminium alloy were obtained at low temperature (80 and 100°C) by the sol-gel dip-coating technique starting from titanium tetra-isopropoxide solution in ethyl alcohol. The preparation was carried out in the presence of acetic acid with both functions of catalyst and chelating agent. The curing temperatures used for these coatings are between 80 and 100°C, low enough to make such coatings suitable to incorporate additives such as organic inhibitors or polymeric nanoparticles. The coated samples were characterised by scanning electron microscopy and energy-dispersive spectroscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy (EIS). Compact coatings with a thickness of 500 nm, consisting of amorphous and nearly stoichiometric titanium dioxide, were obtained. EIS results revealed an effective corrosion protection of the substrate for more than 120 h of immersion in 3.5 wt-% NaCl aqueous solution.

Evaluating the Electrochemical and In Vitro Degradation of an HA-Titania Nano-Channeled Coating for Effective Corrosion Resistance of Biodegradable Mg Alloy

“…The mixture was stirred continuously for 1 h at 45 • C at 600 rpm [15]. Being a chelating agent, acetic acid limits the hydrolysis of titanium alkoxide [16]. The cylindrical polished ZM21 Mg substrate was dipped in TiO 2 sol with a dipping rate of 10 mm/min, soaked for 1 min, and withdrawn at a lift speed of 5 mm/min.…”

Hybrid Ceramic Self-Healing Coatings for Corrosion Protection of Al Alloys in 3% NaCl Solution

“…Over the years, many researchers have been working on different coatings and coatings' techniques [2,3]. From phosphate or cerium-based conversion coatings [4,5], hybrid sol-gel organic-inorganic coatings [6][7][8][9], to physical vapour deposition (PVD) aluminium-doped zinc oxide films [10][11][12], high velocity oxygen fuel (HVOF) titania sprayed coating [13], sol-gel SiO 2 , and ZrO 2 [14,15] have been extensively investigated as alternatives for chromate-base conversion coatings. More recently, attempts to develop self-healing coatings have been made to protect Al alloys from corrosion [16][17][18][19].…”

“…For this reason, the sol-gel route in depositing coatings has gained interest [9,14,[20][21][22][23][24]] over the years. This is due to a variety of reasons, which are linked to the temperature used during the process and low environmental impact of the reactant used in the process [9].…”

“…For this reason, the sol-gel route in depositing coatings has gained interest [9,14,[20][21][22][23][24]] over the years. This is due to a variety of reasons, which are linked to the temperature used during the process and low environmental impact of the reactant used in the process [9]. The sol-gel process has the benefit of reducing the costs incurred during the Nesterova [40,41] developed a coating composed of a matrix made of epoxy resin with microcapsules based on poly(urea-formaldehyde).…”

The Corrosion Inhibition of AA6082 Aluminium Alloy by Certain Azoles in Chloride Solution: Electrochemistry and Surface Analysis

“…Surface modification by either laser shock peening without ablative coating [14] or polyvinyl alcohol fibrous coating [16], as well as by the application of a titania coating [17], was employed to mitigate the corrosion of AA6082 aluminium alloys in chloride-containing solutions. In addition, sodium molybdate dehydrate was used by Panagopoulos et al [18] as a corrosion inhibitor for the AA6082 aluminium alloy in a 0.01 M NaCl solution.…”